Free Terratec 512i Digital with Purchase of Mediator

[tjaoz]

@Crumb

Mediator for A4000 has true DMA. From the Elbox Mediator PCI 4000 website:
---
• Busmastering/DMA in all PCI slots
Mediator PCI supports the busmastering mechanism in all its PCI slots. The PCI cards in the busmaster mode can offer extremely fast DMA access (up to 132MB/s)
without any CPU load. Up to five PCI busmaster cards may be used simultaneously in Mediator.

• SDRAM/SGRAM of PCI gfx card as a DMA buffer
Mediator PCI 4000 can use part of the graphic card memory for Amiga system needs. Thus, the entire system gains in effectiveness as graphic card's SDRAM/SGRAM
memory modules are about 10x faster than FastRAM memory in Amiga turbo cards. With very short access time in SDRAM/SGRAM, several PCI busmaster cards may use this memory simultaneously. The PCI cards may then rush at the data transfer rate of up
to 132MB/s without any CPU load whatsoever.

• DMA to A3/4000 motherboard space
Mediator PCI 4000 includes a busmastering controller supporting transfers between PCI cards and the A3/4000 motherboard space.
---

Due to the A4000 design limitation DMA to A3/4000 motherboard cannot reach 132MB/s which is required by PCI specification for such transfers. It is why Elbox has not used this transfer method for the busmaster PCI cards. Elbox has implemented DMA to the A4000 motherboard in Mediator 4000 for the other purposes.  This mechanism  is prepared to allow SkarkPPC cards to access the A4000 motherboard registers. Mediator PCI 4000 has the jumper named MASTER for this mode activation.

AFAIK G-Rex forces the PCI busmaster cards to do DMA to the turbo card memory but this mechanism in Grex is much too slow for problem-free work. It is why Grex boards have so many problems with the simultaneous operation of more than one PCI busmaster card in the system. This is probably one of the reasons why there is only so few drivers for Grex. There is not sense to develop drivers for new PCI cards if they cannot co-operate with others.

[tjaoz]

@Crumb

that's a kludge, no one would need a DMA buffer if it had real DMA access to the motherboard.

No. DMA access to the A4000 motherboard is too slow for PCI cards.
BTW DMA is not needed for operation of some cards at all: Voodoo and Ethernet 10Mbps never use DMA.

What they don't tell you is that the cpu moves slooowly that data from the gfx ram to the fast ram.

CPU sends data from the graphic card memory to fast ram as fast as the turbo/processor card allows. Some turbo cards do it faster (e.g. Apollo cards), other perform slower (e.g. Blizzard cards). This speed has nothing to do with Mediator. Mediator is prepared for much higher
speeds, up to 132MB/s.

good try... old busters like 6-7 don't have Zorro3 DMA implemented and mediators 3k work as they do with Buster11

What is a problem? It is obvious that if you would like to use DMA to the motherboard you need to update the buster to rev.9 as a minimum.

Zorro3 should give you a bandwitch of 16MB/s with a gfx card (like a CV64 not 3D), not around 10MB (on the 4k version) like now with a Mediator4k or a Picasso4...

This bandwidth depends on the processor card, not on Mediator.

first of all, I don't like the idea of needing a ppc to have proper pcis, but sorry, G-Rex HAS lots of drivers: TV, Terratec sound, Voodoo, ethernet 100, ethernet 10,

I have never heard that anybody has more than two stable operating DMA cards with a Grex.
So, drivers for them are useless ;-)

even USB (unreleased)...

USB for Grex is vapourware.

BTW it also has OpenPCI support and it seems that when a Mediator version of this library was going to be released the DMA stuff worked much better with G-Rex...

OpenPCI is nothing interesting for Mediator users. Mediator has MANY more drivers than other PCI solutions. See here  :-D

[tjaoz]

@Crumb

BTW G-Rex users had Terratecs playing music long time before Mediator users

BTW. Mediator users had SB128 cards playing music long time before Grex users had sound drivers at all. :-)

And If I remember correctly they had Voodoo5 CGX drivers before Mediator.

 Mediator users used Voodoo5 when Grex was not there at all  :-D

Their TV program is truly skinable, have you seen it? I'd like to know how it is programmed...

Mediator has many excellent TV programs. The best are SuperTV and TvR.

"Prometheus are a good board but not a real solution, because it is only Zorro based."
Excuse me? The 3000/4000 versions of the mediator connect are connected to the Zorro3 bus... The only thing against it that I have is that it's difficult to update and that it fits bad in my A4000T...

Prometheus is not supported any more. The guy who designed it withdrew from this project altogether. He even sold his own Prometheus recently.

"Mediator is a good piece of hardae, with fast drivers. " I'd like to see some benchmarks  Their Ethernet drivers seems to be quite slow...

Slow? Their drivers are excellent and very fast. I had about 950kB/s with an Ethernet card.

for example I think that the performance of their crappy DMA hack is worse than Elbox thought initially and that's the reason they don't release SCSI/IDE drivers... A Vapourware-SharkPPC probably would make all these Mediator problems dissapear... but with current hardware their implementation seems a little crap.  

In my opinion the DMA gfx buffer idea developed by them is an excellent solution to bypass limitations of present-day turbo cards.

If you really need to call something a "crappy DMA hack," please reserve this  for something like April chips for the ArticiaS. Here it is justified if using April chips does not solve all DMA problems with the ArticiaS.

OS4 will not have G-Rex drivers, so I guess my only option would be the Mediator4kT :-/

A good choice!

[tjaoz]

@Crumb

Excuse me but Zorro3 scsi cards use DMA without problems the bandwitch is more than enough to develope scsi drivers or ethernet100 drivers that write directly to the fast ram.

 The fact that DMA access speed to the A4000 motherboard is sufficient for Zorro cards working in the DMA mode does not mean it is sufficient for PCI cards in the DMA mode.

BTW can you prove that using the cpu to move data from a ZorroIII memory area to fastram is faster using the cpu than using DMA?

It depends on the situation.
When many small data packets are transmitted over USB or over a network the USB controller or the FastEthernet card collect these packets and store them in a large buffer in the graphic card memory without loading the Amiga system at all. When the buffer is full, the processor copies the entire buffer in one go. With this mechanism, effective transmission speed may be higher than in the situation of a PCI card initiating transmission of DMA to the computer’s memory for each data packet.

The problem is that the speed is limited by the mediator to ~9MB/s (remember that I'm talking about A3000/4000 version, and they work in a slightly different way than A1200 versions...)

AFAIK this speed is usually rather 10-12MB/s not 9MB/s and it depends on the A3/4000 processor’s card model. I saw a bustest of A3000 with Mediator and Voodoo3. The long words write speed was over 11MB/s.

Maybe you are talking about the 1200 version, which only has 2 DMA slots. In the G-Rex 4000 all slots have DMA.

No. I am speaking about all G-rex versions. No more than two DMA cards can operate with Grex 4000 in a stable way. In Grex 1200 there is only one or two (depending on version) slots in which DMA PCI cards can be fitted. More DMA PCI cards cannot be used at all.

The only driver Mediator has and G-Rex has not is USB.

AFAIK OpenPCI Fast Ethernet driver does not work with Grex (it does on Amithlon only) and Grex do not have SB 128 drivers. You can find a comparison between PCI cards supported in Amiga PCI busboards here. It is from 1 October 2002.

Anyway you can't register Poseidon if you buy a Spider now,

I bought Spider last year :-)

So I guess I can say that the Spider is "vapourware" because you have not (legal) way to make it work (or you won't have in 10 days if Elbox doesn't come to an agreement with Chris Hodges).  

Elbox has had an agreement with Hodges since September 2002. See here and here.

[tjaoz]

@Crumb

I doubt that because the first Voodoo5 drivers were CGX, see old vgr news archive...

In the vgr news site, many products and drivers appear, which are pure vapourware, like USB cards and drivers for Grex.

It is supported by OpenPCI.library, as the Prometheus is well documented the drivers developed in other OpenPCI.library compliant systems work without modifications.

I have not heard of anybody with these OpenPCI drivers working with the Prometheus.
Prometheus does not have DMA to A3/4000 motherboard and does not have working DMA between PCI slots. When the Matay company existed  they informed about the firmware update but this update has never worked properly, AFAIK.

It was stupid from Elbox to force Titan not to release it...

Titan received Mediator SDK and Elbox pci.library documentation to write drivers for Mediator, and not to write his own pci library.

they didn't want people saw that they can make work an Ethernet100 without buying their MMCD...

What? So why Titan has NOT done these drivers for Mediator using Elbox pci.library? That was the purpose for which he received Mediator SDK from Elbox.

"Slow? Their drivers are excellent and very fast. I had about 950kB/s with an Ethernet card."
Pretty poor for an Ethernet100

I wrote about Ethernet (10Mbps) card, not FastEthernet (100Mbps). Can't you see the difference?

"In my opinion the DMA gfx buffer idea developed by them is an excellent solution to bypass limitations of present-day turbo cards."
In mine opinion it is a hack, but it is crappy because you get less speed from a PCI gfx card than from a well made Zorro3 gfx card.

Sorry? What does PCI gfx card speed have to do with the DMA gfx buffer solution?
Voodoo gfx card does not work in DMA.

[tjaoz]

@platon42

tjaoz (Rat) and you aren't siamese twins by any chance? Because you always say the same.

platon42 (Hodges) and you aren't siamese twins by any chance? Because you always say the same.

 900KB is really poor. My HydraNexus (10MBit) did about 700KB with AmiTCP.

 It is rather your HydraNexus, which is poor. As I wrote my Ethernet (10Mbps) NE2000 card in Mediator runs at 900KB.

[tjaoz]

@AmiGR

About the Articia stuff... You don't really know what
you're talking about, do you? You know about one single
bug and think that every bug is incarnations of this...

If you are so knowledgeable, why don't you tell us more about these bugs in Pegasos/April2 hardware?